PLATE LXXIII. 



I'las. 



1. Clathrulina elegans Cienk. x 300. 



2. Hedriocy.His spinifera Brown, x 2400. ' 



3. M. spinifera, portion of test further enlarged. x 5000. 



4. H. spinifera, optical section showing portion of capsule 



and plasma with nucleus and contractile vacuole. 

 X 5000. 



Figs. 2-4 from drawings by J. M. Brown. 



